The present invention relates generally to heat seal splice assemblies, and more particularly, is directed to a heat seal splice assembly for butt splicing together two webs of a thermoplastic material.
Heat seal splicing assemblies are known in the art, for example, from U.S. Pat. No. 5,669,998 to Ward et al. However, this assembly is relatively complicated, since it requires two completely separate sub-assemblies, each including its own slide bar assembly and nip bar assembly. During a splice operation, the sub-assemblies on both sides of the apparatus must be pivoted in opposite directions, since a component from each sub-assembly is used during each splice, thereby rendering the heat splicing assembly more costly and more complicated to operate.
A heat seal splicing assembly in which there is a single heat sealing element with two different back plates therefor is known from U.S. Pat. No. 3,610,547 to Anderson. However, this arrangement becomes relatively complicated since a turret assembly must be provided for the webs, requiring additional space.
U.S. Pat. No. 3,705,069 to Elrod discloses another heat seal splicing assembly. Although this assembly is simpler than the aforementioned assemblies since there is a single mandrel against which the webs are heat sealed, the mandrel is stationary. As a result, the machine must be shut down when it is necessary to provide a heat splicing operation. This, of course, is contrary to modern day splicing machines where the webs are to continue running during a splicing operation.